1. Field of the Invention
The invention relates to an electrical wheelchair with spliced front and rear wheel drive mechanism, in particular, an improved ergonomically-designed operation method for easy turning the wheelchair around.
2. Description of the Prior Art
The drive method of an electrical wheelchair of the prior art mainly comprises either the front wheel drive or the rear wheel drive. The front wheel drive provides a very sensitive response, easy to operate and turn the wheelchair around, suitable for driving in indoor or an area with limited narrow space. The rear wheel drive maintains constant stability with no displacement, good for driving in outdoor and long journey.
The operation of the front wheel drive and the rear wheel drive differs greatly. The prior art of the electrical wheelchairs are usually outfitted with both the front wheel drive and the rear wheel drive in an attempt to offer the drive a broad choice. This arrangement inevitably adds more loads to the wheelchair and renders the structure more complicated and the price higher.
Another wheelchair is designed with a rotary chair and one drive mechanism, permitting the driver to shift either the front wheel drive or the rear wheel drive as he desires to rotate the wheel chair.
However, this rotary chair design never puts into account the general habit the driver operates the wheelchair. In the practical operation, the driver pushes the shift rod forward to drive forward and pull the shift rod backward to make a reverse movement. The wheelchair can be put in the reverse movement when it is shifted from the front wheel drive to the rear wheel drive. But the driver is used to push the shift rod forward to make the wheelchair in the reverse movement or vice versa, which defies the proper operation and leads to a worry of accident. In short, it is not a good design.
In addition, the rotary chair of the prior art of an electrical wheelchair normally provides the front footplate. When the chair is rotated to the rearward position, there is no footplate for the drive to plate his feet. Furthermore, the protruded footplate becomes a hindrance for parking and collision.
It is clearly seen that there exist many shortcomings in the design of the prior art of an electrical wheelchair, requiring prompt improvement.
Viewing the above mentioned shortcomings the front wheel drive and the rear wheel drive of an electrical wheelchair inheres, the inventor has dedicated for years to the renovation and improvement of the electrical wheel and come with a successful electrical wheelchair with spliced front wheel drive and rear wheel drive.
The primary object of the invention is to provide an electrical wheelchair with spliced front wheel drive and rear wheel drive. When the chair is rotated, the power shift rod is therefore automatically shifted in the opposite position, convenient for the driver to drive in the way as he is used to be.
Another object of the invention is to provide an electrical wheelchair with spliced front wheel drive and rear wheel drive, easy for the driver to get familiarity with new driving technique in the new electrical wheelchair and attain more safety in driving.
Another object of the invention is to provide an electrical wheelchair with spliced front wheel drive and rear wheel drive with more comfort for the driver to sit on.
The electrical wheelchair with spliced front wheel drive and rear wheel drive of the invention comprises a wheel frame and a chair. The wheel frame is equipped with a hollow column with a locating ring on its top. A semi-circular protrusion is placed on the surface of the locating ring. The wheel frame provides a power rod for controlling the moving direction of the wheelchair. There are two foldable footplates erected, one in the front side and the rear side and the footplate is folded when not in use. Beneath the chair, there is rotary shaft inserted in the hollow column. Along the side of the rotary shaft, there install two locating seats, a control stick passing through the holes of the locating seats. The control stick is locked in the space between two locating seats by the locking mandrel. The mandrel has a hump to form a locating pin which inset in the chute on the periphery of the locating ring. The mandrel is mounted with a recoil spring. On the correspondent opposite position of the locating ring, there installs a micro switch. When the driver wants to change the chair direction, he shifts the control rod, the locating pin departs the locating chute to render the chair a free rotation. At this moment, the locating ring moves simultaneously with the hump which eventually contacts the micro switch and the power stick changes the moving direction according to the ergonomic operation.